io.trino.operator.window.PercentRankFunction Maven / Gradle / Ivy
/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.trino.operator.window;
import io.trino.spi.block.BlockBuilder;
import io.trino.spi.function.RankingWindowFunction;
import io.trino.spi.function.WindowFunctionSignature;
import static io.trino.spi.type.DoubleType.DOUBLE;
@WindowFunctionSignature(name = "percent_rank", returnType = "double")
public class PercentRankFunction
extends RankingWindowFunction
{
private long totalCount;
private long rank;
private long count;
@Override
public void reset()
{
totalCount = windowIndex.size();
rank = 0;
count = 1;
}
@Override
public void processRow(BlockBuilder output, boolean newPeerGroup, int peerGroupCount, int currentPosition)
{
if (totalCount == 1) {
DOUBLE.writeDouble(output, 0.0);
return;
}
if (newPeerGroup) {
rank += count;
count = 1;
}
else {
count++;
}
DOUBLE.writeDouble(output, ((double) (rank - 1)) / (totalCount - 1));
}
}